Distributor duct with flexible baffle plates

ABSTRACT

A distributor duct for a pressure airflow through a baking or drying oven has a lengthwise elongate outlet into which are transversely fitted a plurality of spaced-apart flexible baffle plates held in position by being each snapped in a pair of notches formed in the sidewalls of the outlet. The notches are at a distance from each other which is less than the distance between the engaged sides of the baffle plates thereby forcing the plates into a curved configuration and tensioning the plates against the notch walls.

United States Patent Barteleit et al.

[ Feb. 22, 1972 DISTRIBUTOR DUCT WITH FLEXIBLE BAFFLE PLATES Inventors: Ulrich Barteleit, Kornwestheim; Walter Regenscheit, Zuffenhausen; Helmut Schriider. Ludwigsburg; Erich Wolf, Wangen, all of Germany Werner 8r Pfleiderer, Stuttgart-Feuerbach, Germany Filed: Sept. 19, 1969 Appl. No.: 859,375

Assignee:

Foreign Application Priority Data Oct. 4, 1968 Germany ..P 18 01 201.6

US. Cl ..98/121 Int. Cl

Field of Search [56] References Cited UNITED STATES PATENTS 2,618,331 11/1952 Hicks et al. ..98/121 X 2,650,393 9/ 1953 Coward ...52/473 X 3,120,036 2/1964 Minds ...52/473 X 3,339,330 9/1967 Minds ..98/121 X Primary Examiner-Meyer Perlin Assistant ExaminerW. C. Anderson Attorney-Plane & Baxley [5 7] ABSTRACT A distributor duct for a pressure airflow through a baking or drying oven has a lengthwise elongate outlet into which are transversely fitted a plurality of spaced-apart flexible baffle plates held in position by being each snapped in a pair of notches formed in the sidewalls of the outlet. The notches are at a distance from each other which is less than the distance between the engaged sides of the baffle plates thereby forcing the plates into a curved configuration and tensioning the plates against the notch walls.

8 Claims, 6 Drawing Figures PAIENIEBFEB22 m2 FIG.3

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m 0 TE ma r NR 9 3 H C m U 'IIIIIIIIIIII [Am M SMW BACKGROUND The provision of a plurality of baffle plates in distributor ducts of the general kind above referred to serves to impart to the airflow emanating from the discharge opening a uniform flow direction along the entire length of the discharge open- I Both the manufacture and the installation of baffle plates as now known are time consuming and correspondingly costly. A further disadvantage of preformed and fixedly mounted baffie plates is that the width of the discharge opening as defined by the baffle plates cannot be readily changed.

THE INVENTION It is a broad object of the invention to provide a novel and improved distributor duct of the general kind above referred to which has the advantage of a substantial simplification of the manufacture and mounting of the baffle plates.

The afore-pointed-out objects, features and advantages of the invention and other objects, features and advantages which will be pointed out hereinafter, are obtained by providing baffie plates in the form of initially flat substantially rectangular plates made of elastic material and inserting the same into notches which are formed in the sidewalls bounding the discharge opening and disposed in alignment. The spacing between each two associated notches is smaller than the distance between two opposite sides of the plates in the plane condition thereof. As a result, a plate when snapped with these sides into the notches is automatically forced into a correspondingly curved configuration. Moreover, the now-tensioned plates are retained in the notches due to the pressure with which they engage the wall edges defining the notches. In other words, baffie plates according to the invention are automatically retained in position and are also automatically shaped by being snapped into the notches.

According to a further aspect of the invention, the notches forming slots in the sidewalls of the distributor duct define at their outer ends, that is, at their ends remote from the distributor duct proper, openings for conveniently inserting the flat plates into the notches thereby further simplifying the mounting of the baffle plates in a minimum of time.

The notches in which the plates are fitted have advantageously a V-shaped outline thus safely retaining the plates in position. Moreover, each slot edge facing the convex side of the respective plate is preferably concavely curved and has a curvature which is more pronounced than the curvature of the plate thus facilitating the assembly of the plates and also the disassembly thereof, as will be more fully explained hereinafter.

The invention also provides that the sidewalls defining the width of the discharge opening are displaceable with reference to the distributor duct proper and each other and that the baffie plates inserted into the slots are so dimensioned that the spacing between the sidewalls of the discharge opening can be varied within a desired range without dislodging the baffle plates from their positions in the sidewalls.

If the distributor ducts are designed for carrying hot air or combustion gases as is the case, for instance, in baking or dry ing ovens, it is advantageous to make the rectangular baffle plates of spring steel having a gauge from 0.1 to 0.5 mm. preferably 0.2 mm.

In the accompanying drawing several preferred embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

FIG. I is a diagrammatic side view of a distributor duct according to the invention;

FIG. 2 is a cross section of FIG. 1;

FIG. 3 is an enlarged detail view of a portion of the duct indicated in FIG. I by a dash-dotted circle;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a fragmentary view similar to FIG. 4 but showing a modification thereof; and

FIG. 6 is a fragmentary view similar to FIGS. 4 and 5 and showing a further modification.

' Referring now to the figures in detail, there is shown by way of exemplification a distributor duct 1 of box-shaped configuration as is conventional for such ducts. Air or gas can enter the duct through an inlet opening 2 at the upper end thereof. A lengthwise elongate discharge opening 3 defined by two outwardly extending sidewalls 4 is formed in one of the sidewalls of the duct. A plurality of baffle plates 5 are crosswise disposed between the walls 4 and direct the air or gas streams emanating from thedischarge openings 3 in substantially the same direction over the entire length of the opening. The flow direction of the air or gas entering the duct is shown in FIG. 1 by a vertical arrow and the outflow direction is indicated in FIG. I by horizontal arrows.

According to the invention the baffle plates 5 are initially in the form of flat substantially rectangular plates made of suitable elastic material. The plates are inserted into pairs of slots 6 formed in sidewalls 4 in aligned relationship. As can best be seen in FIG. 3 the slots, preferably produced by stamping, terminate in V-shaped notches 7. The distance'A between each two notches is smaller than the length L of each plate measured when the same is in its flat or plane position as is indicated in dashed lines in FIG. 3. As is now evident,'the plates when snapped into notches 7 are forced into the curved positions shown in FIG. 3 in full lines. The inlet and outlet angle of each baffle plate 5 is determined by the location of notches 7 of slots 6 and also by the ratio between distances A and L.

Each slot 6 defines at the outer rim 8 of sidewalls 4, that is, at the edge remote from the distributor duct, an opening 9 facing toward the duct. Moreover, the edge 10 of each of the slots, that is, the edge facing the convex side of the respective baffle plate 5 has a more pronounced curvature than the curvature of plate 5 so that a gap 11 is formed between plate 5 and the respective edge 10. This gap facilitates insertion of the initially flat plates 5 through the openings 9 as defined by rims 8 into the slots 6 and forcing of the plates into the notches 7 to effect curving and tensioning of the plates.

FIG. 3 shows the position which is occupied by a still flat plate during the mounting operation. If pressure is now exerted upon the midportion of the plate in the direction of arrow P, the plate is flexed until it abuts against edge 10 or at least until it is forced into a position in which the respective two opposite sides of the plate will snap into notches 7. Upon release of the pressure, the plate will recover slightly and it is now retained due to its remaining tensioning in the notches 7 in the form of a curved plate. The V-shape of notches 7 also assures that each plate is accurately retained in a predetermined position.

FIG. 4 shows that the width B of each plate used for forming a curved baffle plate is larger than the spacing C between sidewalls 4 bounding the discharge opening 3. Such dimensioning of the plates effectively prevents sliding of the plates out of slots 6. Moreover, it permits a change in the distance C between the sidewalls 4 and thus in the dimensions of discharge opening 3.

FIG. 5 shows diagrammatically sidewalls 4a which are secured to wall Ia of the duct by means of bolts 12 fitted in elongate slots 13. As is evident, this arrangement permits displacement of sidewalls 4a within the range permitted by the length of slots 13.

According to FIG. 6 sidewalls 4b are outwardly diverging so that thedischarge opening 3 functions in the manner of a diffuser.

Any material which has sufficient strength and elasticity may be used for the baffle plates. Spring steel having a gauge of 0.1 to 0.5 mm. especially 0.2 mm. has been found to be particularly suitable for distributor ducts used in baking or drying ovens.

What is claimed is:

l. A distributor duct for conducting a flow of pressure air in a pressure air utilizing installation, said distributor duct comprising in combination:

a generally tubular duct having in its wall a lengthwise elongate discharge opening, the lengthwise wall edges bounding said opening being continued by outwardly extending sidewalls;

a plurality of substantially rectangular baffle plates made of elastic material; and

mounting means releasably retaining said baffle plates spaced apart between said sidewalls substantially transverse thereto;

said mounting means including for each of said baffle plates a pair of crosswise aligned slots in two adjacent sidewalls, the edges of each slot of each pair of slots defining an inner and an outer receiving notch, the lengthwise edges of each slot converging adjacent to said wall of the tubular duct, said converging slot edges defining the inner notch, the outer notch being disposed adjacent to the outer rim of the respective sidewall thereby providing space for the insertion of the baffle plates into the slots and the notches, the distance between the two notches in each sidewall being smaller than the distance between two opposite sides of the baffle plates, said baffle plates being force fitted with said opposite sides into the notches within the slots of the adjacent sidewalls thereby imparting a corresponding curvature to each of said baffle plates.

2. The distributor duct according to claim 1 wherein each of said notches has a substantially V-shaped configuration, the apices of the inner and outer notches facing in opposite direction.

3. The distributor duct according to claim 1 wherein each slot edge in which the outer notch of the respective pair of notches is formed has a concave curvature with reference to the convex curvature of the facing side of the respective baffle plate, said concave curvature being more curved than said convex curvature thereby defining a gap between the two curvatures.

4. The distributor duct according to claim 1 wherein the distance between the two other opposite'sides of each baflle plate is larger than the distance between the respective adjacent sidewalls.

5. The distributor duct according to claim 1 and comprising adjustable means for varying the spacing between said sidewalls.

6. The distributor duct according to claim 1 wherein the sidewalls diverge outwardly with reference to each other.

7. The distributor duct according to claim 1 wherein the baffle plates are made of spring steel having a gauge between 0.1 and 0.5 mm.

8. The distributor duct according to claim 7 wherein the gauge is 0.2 mm.

i i i 

1. A distributor duct for conducting a flow of pressure air in a pressure air utilizing installation, said distributor duct comprising in combination: a generally tubular duct having in its wall a lengthwise elongate discharge opening, the lengthwise wall edges bounding said opening being continued by outwardly extending sidewalls; a plurality of substantially rectangular baffle plates made of elastic material; and mounting means releasably retaining said baffle plates spaced apart between said sidewalls substantially transverse thereto; said mounting means including for each of said baffle plates a pair of crosswise aligned slots in two adjacent sidewalls, the edges of each slot of each pair of slots defining an inner and an outer receiving notch, the lengthwise edges of each slot converging adjacent to said wall of the tubular duct, said converging slot edges defining the inner notch, the outer notch being disposed adjacent to the outer rim of the respective sidewall thereby providing space for the insertion of the baffle plates into the slots and the notches, the distance between the two notches in each sidewall being smaller than the distance between two opposite sides of the baffle plates, said baffle plates being force fitted with said opposite sides into the notches within the slots of the adjacent sidewalls thereby imparting a corresponding curvature to each of said baffle plates.
 2. The distributor duct according to claim 1 wherein each of said notches has a substantially V-shaped configuration, the apices of the inner and outer notches facing in opposite direction.
 3. The distributor duct according to claim 1 wherein each slot edge in which the outer notch of the respective pair of notches is formed has a concave curvature with reference to the convex curvature of the facing side of the respective baffle plate, said concave curvature being more curved than said convex curvature thereby defining a gap between the two curvatures.
 4. The distributor duct accordIng to claim 1 wherein the distance between the two other opposite sides of each baffle plate is larger than the distance between the respective adjacent sidewalls.
 5. The distributor duct according to claim 1 and comprising adjustable means for varying the spacing between said sidewalls.
 6. The distributor duct according to claim 1 wherein the sidewalls diverge outwardly with reference to each other.
 7. The distributor duct according to claim 1 wherein the baffle plates are made of spring steel having a gauge between 0.1 and 0.5 mm.
 8. The distributor duct according to claim 7 wherein the gauge is 0.2 mm. 